394157749 has 2 divisors, whose sum is σ = 394157750. Its totient is φ = 394157748.

The previous prime is 394157747. The next prime is 394157759. The reversal of 394157749 is 947751493.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 347822500 + 46335249 = 18650^2 + 6807^2 .

It is a cyclic number.

It is not a de Polignac number, because 394157749 - 2¹ = 394157747 is a prime.

Together with 394157747, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394157741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197078874 + 197078875.

It is an arithmetic number, because the mean of its divisors is an integer number (197078875).

Almost surely, 2^394157749 is an apocalyptic number.

It is an amenable number.

394157749 is a deficient number, since it is larger than the sum of its proper divisors (1).

394157749 is an equidigital number, since it uses as much as digits as its factorization.

394157749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 952560, while the sum is 49.

The square root of 394157749 is about 19853.4064835232. The cubic root of 394157749 is about 733.2015195361.

The spelling of 394157749 in words is "three hundred ninety-four million, one hundred fifty-seven thousand, seven hundred forty-nine".